The only purpose for copper that I have seen on railroad tracks is as a connector between rail ends for signal conductivity purposes
central pacific
The North had more miles of railroads tracks then the South
Copper provides the conductive tracks for the circuit. They connect each component together.
The North had more miles of railroads tracks then the South
Trains drive on railroads or tracks.
That's unknown ... tracks to guide cars were around long before railroads were invented.
In the west.
That allows the tracks to expand, in case of heat.
Inside mines. Long before railroads were built.
They assisted in the acquisition of land for the tracks to go through.
Wherever they want the train to go. Or under the wheels.
They gave them lots of land to build the tracks on. Another answer: railroads were given checker-board parcels of land on which to build their road beds, and afterward the railroads could sell the land for profit to settlers.